The unit discusses and defines hydrostatic pressure. Explain what hydrostatic pressure is and how this term relates to Néry's talk. Explain what the term "blood shift" means and how it works. Describe what happens when Néry falls below 80 meters in depth. How must Néry react in order to survive, and even enjoy, falling to such depths? Néry describes many aspects of the entire experience of free diving that he finds appealing. What aspect of the free-diving experience that Néry describes appeals to you most? Why?